Kitty is a hunched, hesitant figure as she quietly recounts how a boy aged 14 put her out of teaching.

"First he threw a chair at me, then he threw his school bag straight in my face, then he punched me on my upper arm and then on my nose - which broke it."

The fracture has mended, although she still has a trapped nerve which causes a lot of problems.

But the mental effects of those 25 seconds in a modern languages lesson two years ago are still plain to see.

Stunned

Kitty was aware that teachers who attempted to defend themselves in such circumstances could end up being accused of assault themselves.

In the event, when it happened to her, she did nothing.

"I was shocked out of my wits and didn't do a single thing to defend myself," she said.

She has retired from teaching after 14 years on the grounds of ill health, suffering from post-traumatic stress disorder.

"That has caused me a lot of pain. It is easing, but I am not able to manage very much.

"I can't work."

Expulsion

The police were involved but she does not know - was not informed - whether any criminal charge was brought against the boy.

She says she had "extremely good support" from her school and steps were taken to expel the boy, but his parents took him out of the school before it came to that.

Whether or not her school's management or her employers could have predicted that the boy would do such a thing is an issue being pursued by her solicitor, so she does not speak about that.

But she was greatly heartened to hear a government education minister - Stephen Timms - speaking about assaults on teachers at the National Association of Schoolmasters Union of Women Teachers conference on Tuesday.

His message: Attacks were completely unacceptable.

Taboo subject

"Teachers have known for years that there has been a problem and it's time society started to address it," he said.

"It can't be something we don't talk about, even if we don't know all of the answers.

"We need to break the taboo there's been around this subject for years."

For Kitty, the observation by Mr Timms that everyone had the right to work in a place of safety - and that a school might not be such a place - was an important step forward.

She does not presume to put forward answers either.

She says it would do no-one any good for the boy who attacked her to be incarcerated without help to manage his anger and his violent behaviour.

'Whining'

But her wider concern is for colleagues still struggling and being stressed by "the day-to-day grinding ugliness and unpleasantness of aggressive behaviour and insulting language".

Reluctantly Kitty tells her own story to illustrate to people what "whining teachers" have to put up with.

"It's very, very late in coming, this official acknowledgement that we have a right to work in safety," she said.

Too late for her.

"My abilities, intellectually and emotionally, have been seriously damaged.